• Clay masonry has a service life of +150 years, easily outperforming most other materials
• Clay bricks retain their shape and colour, even after long exposure to the elements
• Bricks are fired at over 1000 degrees Celsius during manufacture, they are completely incombustible and are able to retain their mechanical strength during fires
• The high stability and density of clay masonry enables it to withstand water pressure very well making it very flood resistant

The BDA’s declaration of 500 years of durability and the service life of 150 years underlines the durability and legacy that you will be creating.

Brick offers a sense of stability, it is much more robust than many man-made materials and won’t rot, rust, erode or decay in ever changing weather patterns.

Brick is a solid, permanent and low maintenance material that provides lasting beauty and appreciating value – brick offers true longevity.

• Clay is a natural material which is quarried, crushed, shaped and fired.
• The European Standard for clay masonry units BS EN 771-1 requires a manufacturer to declare a particular size category for each product based on individual brick measurements.
• Different categories take into account the wide range of brick types and different manufacturing methods.
• Tighter tolerances can often be achieved for more regular extruded or wirecut products than with handmade and stock bricks.

Different colours can be created in a number of ways using different raw materials, manufacturing techniques and processes.

Engobed surface treatment

Engobes are liquid colourings consisting mainly of clay minerals.  The engobe is applied to the dried unfired bricks.  During firing the engobe coating is sintered into the surface of the brick creating special colour effects.

Glazed surface treatment

A glassy solution is applied to the dried unburnt bricks. During the firing process, this applied surface coating fuses with the tile, forming a real glass coating.  Unlike engobes, glazes are impervious to water.

Stretcher Bond
Cavity walls originated in late 19th century and insulation was introduced into the building envelope in the 1970’s.  Because the outer leaf is now only half a brick thick stretcher bond has become the most common bond in use. (least number of bricks per m²).

Header Bond
Popular during the 18th century Header bond often employed contrasting brick colours to give a decorative effect. This bond produces a fine, tight wall, but uses so many bricks that it is usually reserved for very high-quality buildings. It’s also used for curved brickwork, as the short faces are easier to build into undulating shapes.

Flemish Bond
From the beginning of the 18th century, the Flemish bond superseded English bond. This style has stretchers and headers alternating within each course.  Flemish bonds can be replicated in the half-brick outer leaf of a cavity wall by using whole bricks as stretchers, while the headers are created by half bricks called bats or snap-headers.

English Bond
This is the oldest pattern, and was commonly used until the end of the 17th century. A course of stretchers alternates with a course of headers. English Bond is considered stronger than Flemish bond, so continues to be used for civil engineering projects, such as bridges, viaducts and embankments.

Garden Wall Bonds
Laying stretchers uses up fewer bricks than laying headers however it is also less strong hence its use in traditional walled gardens and other modest structures.

Stack Bond
In stack bond the bricks do not overlap and therefore the arrangement is inherently weak. To compensate for the lack of bonding, typically bed-joint reinforcement is built into every third bed-joint.

In general, reversible movements are caused by temperature changes.  Irreversible expansion (caused by adsorption of water molecules by the fired clay brick) can be larger and continues, albeit at a reducing rate, for a period of years.

As a general rule in buildings, brickwork expansion joints should be provided every 10-12m maximum.  This dimension reduces to 6m in boundary walls or brick faced parapets.  In addition, movement joints should be provided where brickwork returns are less than 675mm, where there is a change in height or a change in surface finish.

The spacing and thickness of movement joints is related to the detailed design, length and height of the brickwork, together with any requirements for structural restraint.  We would suggest that the Structural Engineer for the project reviews movement joint positions prior to construction.

An indication for normal storey height walls is that the joint width (in mm) should be at least equal to the joint spacing (in m) plus an allowance of typically 30% to allow for the compressibility of the filler and the performance of appropriate sealants – Thus movement joints at 10m centres will need to be approximately 13mm wide.

When brickwork is to be used to clad a reinforced concrete or timber frame, the design should make particular allowance for differential movement.

• Clay bricks, like all materials, expand and contract as temperature rises and falls
• Thermal expansion of the brick will occur due to the range of temperatures experienced, the orientation of walls and the colour of the brick
• A greater influence on the overall movement of clay bricks is the long term effect of moisture
• The location and size of movement joints must take into account the characteristics of the product, the design and dimensions of brickwork panels, and their relationship in plan form
• As a general rule in buildings, brickwork expansion joints should be provided every 10-12m maximum